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Cosmic Night Light 


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Cosmic Night Light 

Written By: Kris DeGraeve 


Alligator clips (1) 

Pliers (1) 

2 pairs is nice, but not necessary 

Screwdriver (1) 

Spring clamps (1) 
or binder clips 

Toothpicks (1) 

Wax paper (1) 


Coin cell battery holder (1) 


for resin. Mine was a 3"x6" rectangular 


Clear resin (6oz-8oz) 
Use catalyst if needed. I used a 
polyester epoxy. but a 2-part one would 
probably be safer. 

Cardboard (1) 

Resin dyes (1) 

/ used blue and yellow to achieve 
colorful, hazy light, plus pearl or white, 
which helps the colors "pop. " 

Masking tape (1) 

Glitter (1) 

/ used silver holographic and star- 
shaped glitter. 

Epoxy (1) 

Cyanoacrylate glue (1) 
aka super or Krazy glue 

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Cosmic Night Light 

LED (10) 

Lightweight wire (1) 
Insulation isn't necessary. 

Coin cell battery (2) 

Resistor (1) 
Use the calculator at This light was 
built using a 56D. , V2W resistor for a 6V 
source. 3.3V diode, and 20mA current, 
but LEDs are forgiving, so you don't 
have to be too exact, and with a small 
array you can use just 1 resistor. 

On/off switch (1) 


I wanted to make a night light with LEDs encased in resin that required no soldering — I can 
solder but I don't really like to. The project turned out to be one of my favorites, and beyond 
being a little tweaky getting all of the LEDs set, it's simple. The power comes from 2 coin 
batteries, so there's no risk of shock. And the finished product is a glossy, atmospheric light 
with a soft glow that looks great between my Martian lunch box and little plastic dudes 
landing on the moon. 

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Cosmic Night Light 

Step 1 — Make a template. 

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Cosmic Night Light 

© Make Projects 

• First you'll need to choose a 
pattern for the LEDs, like a 
constellation. Most people would 
choose the Big or Little Dipper, so I 
went with Leo — it's the best, and 
it nicely fit the dimensions of the 
mold I had chosen. You can search 
online for a star chart, use my 
pattern, or just make one up. 

• To turn your pattern into a 
template, import it into a graphics 
program (I used Illustrator) and 
resize it to fit your mold, leaving a 
W margin around the outside. 
Draw a small circle where each 
LED will be placed. Then draw 2 
connect-the-dots lines that touch 
each LED on opposite sides, one 
for positive and the other for 
negative, making sure the lines 
never cross. 

• In an empty space, draw a 1" circle 
for the battery pack, another circle 
to fit the switch (mine was 3 A") and 
a small rectangle for the resistor. 
Draw more lines and adjust 
positions to complete the circuit: 
the positive side connects to the 
positive battery terminal through 
the resistor and switch, and the 
negative side goes directly to the 
negative battery terminal. Place the 
switch where it will be easy to 
reach, and orient the battery holder 
to make it easy to change 
batteries. Make all lines thick and 

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Cosmic Night Light 

dark so they clearly show through 
your first layers of resin. 

• Finally, draw your mold's outline 
(3"x6" rectangle) around your 
pattern, flip the image (since you'll 
be using your template from the 
back), and print it out. I made 2 
copies, with an extra one to refer to 
and make notes on. You can 
download my template at 4/cosmic. 

• WARNING : Resin and 
epoxy are toxic, dangerous, 
and can damage many surfaces. 
Use only in a well-ventilated area, 
on a well-protected surface, and 
away from kids and pets. Read and 
heed all product safety warnings. 


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Cosmic Night Light 

Step 2 — Cast the face layers. 

LED Wires Battery Clear epoxy 
around LED 


Final black layer 

Black layer 

Optional dyed layer 

First clear layer 
(runs up the sides) 

• You'll start at the face of the light 
and the bottom of the mold. Follow 
the instructions to mix up about 
1 /20z of clear resin, and add glitter 
or other cosmic debris if you like. 
Catalyze it, pour into the mold, and 
tip the mold so resin covers the 
bottom and gets up onto the sides 
a bit. Let it harden completely. 

• I added a second layer of 
blue/green/yellow/pearly colored 
haze — don't do this if you want 
the LEDs to appear as sharp points 
of light. For the haze layer, mix 
another 1 / 3 oz-!/20z of clear resin, 
add glitter, and pour to cover the 
first layer. Add a drop of dye and 
swirl it with a toothpick. Add drops 
of different-colored dyes and swirl 
just until you like how it looks, then 
leave it alone until it's hardened. 
Mixing too much loses the effect. If 
you mess up, pour it out and try 
again. The reason you mix colors 
in this second layer instead of the 
first is that the toothpick can leave 
permanent marks on the mold. 

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Cosmic Night Light 

Step 3 — Test and attach the LEDs. 

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Cosmic Night Light 

• Load the batteries into the holder, 
attach alligator leads, and use them 
to test the polarity of each LED; it 
will light when you connect the 
positive voltage to the LED's 
positive side and negative voltage 
to the negative side. Mark the 
polarity for each. An LED's 
negative side is usually marked, 
but you should test them all 
anyway because you'd be bummed 
to make this project and then have 
the lights not work. 

• Now you'll glue the LEDs, which 
are round on top, upside down to a 
flat surface. This takes patience. 

• Set the mold on top of the template 
and mix up some clear epoxy 
adhesive. Put a drop at each LED 
location and sink an LED into it, top 
down and oriented for wiring. You'll 
want a "cocoon" of epoxy around 
each bulb to let its light shine 
through to the front. The LED will 
probably tip over, so use a 
toothpick to lift it back upright. You 
may have to lift LEDs back up 
about 3 million times before they're 
all set, but the epoxy should gel in 
about 5 minutes. Skipping the glue 
step and trying to set all the LEDs 
in a new layer of resin would give 
you very little time to fix the fallen 

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Cosmic Night Light 

Step 4 — Seal the LEDs. 

• V<? 

• Mix another V20Z of resin and dye it very black — the more opaque, the better. Pour small 
amounts in between the LEDs and let it spread. Then fill the mold up to a level that's just 
even with but not above the plastic backs of the LEDs. This layer hides the wires, 
switches, and batteries from the front. Again, let this layer harden like you mean it at least 
overnight, and until it clicks when tapped. 

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Cosmic Night Light 

Step 5 — Build up the sides. 

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Cosmic Night Light 


• Now we'll build up the walls of the 
night light by pouring resin into the 
mold sideways. I've been working 
on this method for a while, and it 
lets you make a wide range of resin 
enclosures without having to use a 
2-part mold. 

• Cut 2 strips of cardboard IV2" by 
6 1 / 2 "-7". Stack and tape them 
together with masking tape, then 
wrap and tape waxed paper around 
the cardboard so that 1 side is 
smooth waxed paper with no tape. 

• Lay the mold on 1 long side with its 
rim hanging over the edge of a box 
or table. Use spring clamps to clip 
the cardboard strip to the rim, 
smooth side in, to enclose the low 
side of the mold. I used 3 clips 
along the bottom and 1 on each 
side. The waxed paper should form 
a seal against the lip of the mold, 
and resin is viscous, so trust me, 
it'll hold. 

• Set the mold up over newspaper 
and run tape over the top to keep it 
from falling over. Mix up V20Z of 
black resin with optional glitter and 
pour it over the cardboard into the 
side of the mold, about W thick. 
Let it harden, then unclip and peel 
back the strip, and repeat for the 
other 3 sides. I used V20Z of resin 
for each long side and Vioz for 
each short side. 

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Cosmic Night Light 

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Cosmic Night Light 

Step 6 — Wire it up. 

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Cosmic Night Light 

© Make Projects 

• Cut a 3' piece of 24-gauge wire, 
fold it in half, and hook it over the 
positive prong of the LED farthest 
from the battery (check your 
template). Wind the wire between 
the LEDs in overlapping figure- 
eights until you've connected all 
the positive prongs, then bend the 
prongs over the wire with pliers, 
squeezing tight. Repeat this 
process with the negative prongs. 
If an LED pops out, push it back in, 
finish wiring, and reglue it. Make 
sure the clear epoxy seals all the 
way around, or else black resin can 
seep in later and obscure the light. 

• At the end of the positive line, cut 
the wires off 1"-2" beyond the last 
LED and twist the ends with 1 end 
of the resistor. Place the switch 
and battery holder where you want 
them, and twist-connect the rest of 
the circuit with more wire: resistor 
to switch, switch to battery (+), and 
battery (-) to negative line. Trim 
any excess wire. You can super- 
glue loose connections to hold 
them until the final cast. 

• Carefully flip the switch on, and 
make sure all the LEDs light up. 
Fix any that don't. 

• Mix more epoxy adhesive and put a 
dollop over every LED. Keep the 
LEDs on and watch them while the 
epoxy sets; sometimes epoxy will 
slide between wires and take out a 

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Cosmic Night Light 

connection, but then you can turn 
the light back on by pushing with 
pliers or a toothpick. Again, make 
sure it's all really, really dry. 

Step 7 — Pour the last layer of resin. 

• Mix up V20Z or more of dyed black 
resin and pour it into the mold to 
cover the LEDs and fill in under the 
switch and battery holder. Make 
sure you don't pour in so much that 
you disable the switch or make it 
impossible to remove the batteries. 
Let it harden. 

Step 8 — Unmold, turn on, and admire. 

,•«• ; ■ ■'.•*'. 
»*• •' ■■-.■*■ •- ■• J» 

'"'*■■ ■'.''■ :' - : ^^^ 

^ . .»■•.£. •■ ■' ;••■■ 

■■- ■ . 

• Carefully pull away the sides of the 
mold and flex it until your light pops 
out. Handle it gently; even after the 
resin seems hard, it can take a few 
days to set completely. You might 
lightly sand the resin walls in back, 
but otherwise your light is done. 
You can also cover the back with 
felt, secured by glue or velcro. 
Enjoy your new cosmic night light! 

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Cosmic Night Light 

This project first appeared in MAKE Volume 14 . page 70. 

This document was last generated on 2012-11-03 12:39:56 AM. 

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